Laser welding plastics in medical device manufacturing

Daventry, Northamptonshire, UK – German automation specialist Contexo manufactures assembly and test systems for high volume production of medical and pharmaceutical assemblies as well as products for the consumer goods industry.

Typically, these machines will incorporate several different processes such as dispensing, laser welding, pressure testing, sorting and packaging integrated into a single, highly sophisticated manufacturing line. Each of the individual processes are developed in-house in close cooperation with the end-customer to ensure that the various elements of the system meet the specific requirements of the project. This philosophy extends to the joining technologies that may be required for a specific application.

In order to achieve and maintain the required machine cycle time, the individual manufacturing processes themselves need to be fast enough. Another consideration for high speed, high volume joining applications is the preference to eliminate the need for additional materials such as glue or fasteners, which could add considerable cost to the finished product.

When producing parts for the medical and pharmaceutical industries, not only are precision and dimensional accuracy important, but traceability and quality assurance of any joining process used is essential. Of the commonly used joining processes, which include ultrasonics, crimping, and glueing, welding using a diode laser meets all of the pre-requisites such as speed, precision, flexibility and traceability with none of the drawbacks that can be associated with other joining processes.

From a manufacturer’s point of view, welding with a diode laser offers the highest precision, especially in instances where complex structures need to be joined (see figure above). A typical example of an actual project was the requirement to weld a plate with micro channels using a fiber-coupled diode laser in combination with a galvo scanner.

The challenge of achieving precision welding around fine contours with a total weld length of 1.5 m on a surface area of just 10 cm x 12 cm was successfully carried out, a task which would have been very difficult if not impossible using alternative joining technologies

Additional benefits of the laser welding process include the ability to predict and guarantee the process time and also adhere to the stringent “particle free” production standards for medical products.

An increasing demand for laser based plastics welding technology within the medical device manufacturing industry is anticipated. The main reasons for this will be the increasingly sophisticated welding requirements on the components that need to be joined, coupled with more complex welding contours. The ability of the laser to provide a precise, predictable, fast and controllable joining process, especially on compact and complex parts, is why laser welding technology is now being considered by a growing number of product manufacturers at the design phase of new projects.

For further information, emai Rofin-Baasel UK at [email protected]